The undrafted college free agent has been a big part of the NFL since 1950. Fourteen of these players have gone on to become Hall of Famers and countless others have made significant contributions. Despite the exhaustive scouting done on college prospects leading up to the draft, there are players who slip through the cracks -- the NFL's diamonds in the rough.

The key is identifying players with a specific trait that leads to success at the NFL level. Most of these players lack a complete NFL-ready skill set, but they possess one or two characteristics that prove valuable on Sundays. This is a player like Cliff Harris, who went undrafted out of little-known Ouachita Baptist in 1970, but made six Pro Bowls due to his tremendous speed. Joe Jacoby wasn't great at Louisville, but had a valuable trait for offensive tackles: 35.5-inch arms. Jacoby made four Pro Bowls and won three Super Bowls over a 13-year career. And then there's John Randle, who lacked the size and pure speed of conventional defensive tackles in the NFL, but made up for it with unbelievable quickness and competitiveness. Randle hit double digits in sacks in nine different seasons, made seven Pro Bowls and earned a bust in Canton in 2010.

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Through Monday, May 7, there were 459 undrafted free agents signed by NFL teams. The number of signees varies from team to team; this year, Atlanta had the most with 23, while New England had the least with four. Of these players, approximately 50-60 will be on an NFL roster for the first week of the 2012 season. (Fifty-nine made the cut in 2011.)

I have scouted every one of these players. Based on this knowledge, I've provided my top 11 undrafted free-agent hauls by teams this offseason. These rankings are not particularly predicated on the players' college production, but rather on specific traits that lead to production on the NFL level. Every undrafted free agent represents a calculated, low-risk gamble. These are the teams playing their cards best.

I especially like Daniels because of his intelligence and production as a four-year starter at Duke. He displays NFL-caliber speed and reaction skills as a safety. Although Duke isn't much of an NFL factory, Daniels showcased special talent in his collegiate career. McLeod played safety at Virginia, but can transition to corner due to his speed and quickness. Hoffman-Ellis has the unrelenting competitiveness to be a great special teamer in the pros.

All three of these players have special traits that could lead to success at the NFL level, but the most notable player is Nzegwu. He projects as a pass-rush specialist, due to excellent speed -- as evidenced by his 4.55 40 at the Wisconsin pro day -- and a great first step. He's not an every down player, but has the quickness to get to the passer. His game is somewhat reminiscent of Colts sackmeister Robert Mathis, who was a fifth-round pick out of Alabama A&M back in 2003.

Blatnick can be a very good pass rusher. Surprising he wasn't drafted, because he showed a penchant for disrupting action in the backfield, recording 13.5 tackles for loss and eight sacks as a senior. He's gifted with quickness and overall athleticism and seemed to play his best against the best competition (including nine tackles and two sacks at Texas last October).

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Burfict let his weight get out of hand and he has a difficult time taking to coaching (as evidenced by his tendency to freelance within a defense, as opposed to just sticking to his assignments). But this is a guy who's worth taking a chance on because he has the competitiveness to be successful at the position. When he's in shape and properly motivated, he's been dominant. Lamur played safety at Kansas State, but I imagine he may be converted to linebacker. He's big, fast (by NFL linebacker standards) and ultra-competitive, with fine ability to make plays in space. He could become a solid contributor on special teams immediately.

Smith has the speed and quickness that you're looking for in a pass rusher. At 6-foot-2 7/8 and 252 pounds, he posted an impressive 4.59 40-yard dash. The Dolphins are currently reaping the benefits of another speedy pass rusher who was overlooked coming out of college: Cameron Wake. Collins has the competitiveness and size to surprise people at the NFL level. This guy definitely has NFL measurables.

Leary could immediately start at guard, as the Cowboys continue to transition along the offensive line. There are questions about his longevity due to a nagging knee ailment, but this guy is an absolute house at 6-3, 315 pounds and plays with plenty of power. Saalim Hakim is the younger brother of former NFL wideout Az-Zahir Hakim and he offers a similar game with great speed and unbelievable quickness. He lacks experience at a high level, but this is a guy who makes everyone else on the field look slow.

Pleasant played safety at Oregon -- a program that places a ton of responsibilities on its safeties -- but his speed and quickness should allow him to convert to corner in the NFL. He could be an immediate contributor on special teams, but would also be ready to fill in for injured players. His competitiveness jumps off game tape.

Baker lacks extensive game experience, but his length at 6-8 makes him a very enticing tackle prospect. In fact, Baker was an extremely hot commodity right after the draft, receiving one of the largest undrafted rookie signing bonuses at $15,000. He reminds me a little of Jason Peters, who went undrafted out of Arkansas in 2004. There are probably 100 more proven line prospects coming out of college than Baker, but you don't find too many bodies like this.

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Holland exhibited fantastic speed for a linebacker at the Purdue pro day, posting a 4.48 40-yard dash and 6.5 three-cone drill -- which tells you about his exceptional change of direction. He also posted 22 reps on the bench press. As a fabulous all-around athlete, Holland can become an stalwart on special teams in the NFL. Harbaugh knows Thomas well from his time as Stanford's head coach. He played safety with the Cardinal, but could become a corner in the NFL. At Stanford's pro day, Thomas ran a freakishly quick 3.99 short shuttle.

Coleman is extremely hard of hearing, but that didn't stop him from making his mark at UCLA, where he scored 11 rushing touchdowns as a senior. He's big at 230 pounds, but has home run-hitting ability, as evidenced by his 4.56 40 at UCLA's pro day. He's also adept at catching balls out of the backfield. Minnesota is a great place for Coleman, as the Vikings clearly like big backs with Adrian Peterson and Toby Gerhart. Meanwhile, Powell is yet another defensive line prospect out of North Carolina. The 311-pounder is a force on the interior and could develop into a nice run stopper with inside-pressure capability.

Taylor is a pass-rushing specialist who only played on throwing downs at Cincinnati. He's a very raw talent who could really blossom with NFL coaching due to his natural burst off the edge. This is a high-ceiling project worth investing some time and energy on. Tuinei is a specimen at wide receiver, standing 6-4, 220 pounds and posting a 4.53 40 time. He did not benefit from Oregon's run-based offense/uneven quarterback play -- upside galore for Seattle. With his big body, the Seahawks could make this guy into a third tight end, creating mismatches all over the field. Kearse offers enticing speed that can stretch out a defense.